Core cup retaining device



m 24, 1967 s NAmS 3,348,276

CORE CUP RETAINING DEVICE Filed Oct. 1, 1965 f FIG.1

INVENTOR SIGITAS M IKNAlTiS United States Patent 3,348,276 CORE CUP RETAINING DEVICE Sigitas Miknaitis, Chicago, Ill., assignor to Automatic Electric Laboratories, Inc, Northlake, Ill., a corporation of Delaware Filed Oct. 1, 1965, Ser. No. 492,241 8 Claims. (Cl. 24-263) ABSTRACT OF THE DISCLOSURE Apparatus for clamping together cup-core transformer assemblies. A pair of identical, resilient, one-piece retaining elements interlock co-operating male and female legs to clamp together a plurality of cup-core sections. Each retaining element includes a base having a flat portion which provides a distribution of clamping stresses when the retaining elements are flexed and interlocked.

This invention relates to article holding devices and in particular to devices for clamping together a plurality of articles, for example, cup core transformer assemblies.

Cup core transformers have found extensive use in high and low frequency applications, particularly in signaling applications. Various types of adhesives have been used to cement the cores together; however, various conditions of temperature, humidity and mechanical vibra tion and shock have indicated that some holding agent is needed in place of, or in combination with, an adhesive. To this end several mechanical clamping devices have been devised to hold the cup core sections together.

One such mechanical device is a screw assembly which extends through the central apertures of the core sections to a base plate or to the chassis of the associated equipment. A disadvantage of the screw device is that several nuts were needed for locking the core sections under particular contacting pressure; a loosening of the screw device would detune the arrangement. Furthermore, the ideal means of tuning is the provision of a tuning slug in the apertures occupied by the screw arrangement.

Another clamping device comprises a one-piece U- shaped strap arrangement forming a cylindrical cavity and having tabs which are normal to the end of the legs of the U. The arrangement is flexed to insert a core assembly; one end of the core assembly held against the center portion of the U and the tabs bearing on portions which are immediately adjacent the edge of the other end of the core assembly. A drawback of this arrangement is that the said edge portions are under greater stress than the remainder of the end surface, thereby promoting cracking and breaking of the core sections.

One other device which has proven quite successful comprises a U-shaped strap arrangement forming a general cylindrical cavity and having legs of slightly less length than the dimension of core assembly. A base plate is screwed, riveted or bolted to outwardly flared leg ends to clamp the core sections together. A disadvantage of this arrangement is that several piece parts (i.e. strap, base plate, rivets, screws, etc.) must be stocked and assembled.

It is therefore the primary object of my invention to provide a new and improved clamping arrangement.

Another object of my invention is to provide a new and improved clamping arrangement which has the various advantages of the above arrangements and none of the disadvantages.

The present invention involves a two-piece clamping device; however, it should be specifically pointed out that, in keeping with the objects of the invention, the two pieces are identical. Therefore, a feature of the invention resides in the provision of two identical clamp components to realize a clamping device.

Another feature of the invention is the provision of two identical interlocking element each of which has a male and a female portion for mating with the female and male portions, respectively, of the other.

Other objects and features of the invention will become apparent and the invention will be best understood from the following description taken in conjunction with the accompanying drawings of which:

FIG. 1 is a front view of a cup-core type transformer employing an embodiment of the present invention;

FIG. 2 is a top view of the transformer of FIG. 1;

FIG. 3 is a top view of one of the clamping elements according to an embodiment of the invention;

FIG. 4 is a front view of one of the clamping elements according to an embodiment of the invention;

FIGS. 5 and 6 are side views of the element of FIG. 3;

FIG. 7 is a section view of two mated elementsaccording to FIGS. 4, 5 and 6; V

FIG. 8 is a section view of another embodiment of the invention; and

FIG. 9 is a partial section view of another embodiment of the invention.

FIGS. 1 and 2 describe a transformer assembly (without windings) comprising cup core section 300 including an aperture 310, cup core section 400 including an aperture (not shown) which is aligned with aperture 310 for accepting a tuning slug referenced 600, a bobbin 500 having flanges 510 for carrying terminals (also not shown); and a pair of interlocking clamp retaining elements 200.

FIGS. 3 to 7 described retaining element 200 comprising a deformable base including a generally fiat portion 201 having an aperture 203 therein for access to the tuning slug, a portion 211 formed at a slight angle to the plane of portion 291, and portion 221 formed at a slight angle to portion 201. Leg 210 comprises portion 212 which is generally normal to the plane of portion 201. A double bend forms portion 213 of leg 210 having slot 214 therein. Extending farther from portion 213 is portion 215. Leg 220 comprises portion 222 which is generally normal to the plane of portion 201 and tab 223, an extension of portion 222, having a lip 224 which may be pressed from the material of portion 223. Tab 223 may advantageously be bent slightly inward (toward leg 210) to facilitate assembly. Bars 202 which extend substantially normal to the plane of portion 201 seat or position the core sections.

Retaining element 200 is made of a flexible springy material. The slight angle of base portions 211, 221 with base portion 201 provides a spring arrangement and portion 201 exerts an even distribution of forces over the end surfaces of the core sections.

It can be easily seen that an assembler need only to seat the cup core assembly between ears 202 on section 201, invert another element 200 on top of the assembly with unlike legs aligned, and snap together elements 200. FIG. 7 shows the result of snapping two elements 200 together. Tab 223 extends through aperture 214 and is locked in place by lip 224.

Another embodiment of the invention may be seen in FIG. 8. Leg portion 213A is defined by bends opposite that of portion 213. Accordingly, lip portion 224A is on the outer side of portion 223A in order to catch on the edge of slot 214A.

Still another embodiment of the invention may be seen in FIG. 9 wherein the female leg comprises portions 212B and 213B, aperture 2143 being provided in portion 213B. Leg portion 22313 is bent back upon itself after being inserted in the aperture 214B and proper compressional forces have been applied to the cores.

-33 Many changes and modifications may be made in the invention by those skilled in the art withoutv departing.

from the spirit and scope of the invention and should be included in the appended claims.

What is claimed is:

1. Apparatus for fixedly retaining a plurality of cupcore sections in abutting relationship, said apparatu including a pair of identical resilient retaining elements, each said elementcomprising a deformable base, first and second legs extending from said base, said bases and said legs forming a cavity for said cup-core sections, each of said first legs including a female portion having an aperture therein and a pair of generally parallel portions joined by said female portion, and each of said second legs including a male portion for insertion into the aperture of a co-operating female portion of the other retaining element of said pair, and a lip on said male portion directed against the direction of insertion into the cooperating female portion to engage the edge of the aperture thereinrand secure said elements in locking engagement with said bases deformed to urge said cup-core sections together.

2. Apparatus according to claim 1, wherein each said element is a one-piece resilient structure, and wherein each said base comprises a flat portion for hearing on an adjacent core section, and a plurality of spring portions integral with and at an acute angle to .said fiat portion and said legs for urging said core sections together when said retaining elements are assembled in interlocking engagement.

3. Apparatus according to claim 1, wherein each said base includes a plurality of ear portions normal thereto for aligning said core sections.

4. Apparatus according to claim 1, wherein each said base includes a flat portion, the total length of the core sections to be retained being greater than twice the distance from said lip to the plane of the flat portion of the same unflexed'retaining element.

5. Apparatus according to claim 1, wherein the outermost one of said parallel portions is offset toward the inside of the cavity by said female portion, and wherein said lip is provided on the cavity side of said male portion.

6. The apparatus according to claim 5, wherein said male portion is bent slightly inward to facilitate assembly of said elements.

7. Apparatus according to claim 1, wherein the outermost one of said parallel portions is offset away from the cavity by said female portion, and wherein said lip is provided on the side of said male portion which is away from the cavity.

8. The apparatus according to claim 7, wherein said male portion is bent slightly outward to facilitate assembly of said elements.

References Cited UNITED STATES PATENTS 2,372,067 3/1945 Forbes 336-210 2,429,604 10/ 1947 Boucher et al. 336-210 XR 3,197,167 7/1965 Sturgis 336-83 3,229,998 1/ 1966 Pennington 24-263 XR FOREIGN PATENTS 530,461 9/ 1956 Canada.

DONALD A. GRIFFIN, Primary Examiner. 

1. APPARATUS FOR FIXEDLY RETAINING A PLURALITY OF CUPCORE SECTIONS IN ABUTTING RELATIONSHIP, SAID APPARATUS INCLUDING A PAIR OF IDENTICAL RESILIENT RETAINING ELEMENTS, EACH SAID ELEMENT COMPRISING A DEFORMABLE BASE, FIRST AND SECOND LEGS EXTENDING FROM SAID BASE, SAID BASES AND SAID LEGS FORMING A CAVITY FOR SAID CUP-CORE SECTIONS, EACH OF SAID FIRST LEGS INCLUDING A FEMALE PORTION HAVING AN APERTURE THEREIN AND A PAIR OF GENERALLY PARALLEL PORTIONS JOINED BY SAID FEMALE PORTION, AND EACH OF SAID SECOND LEGS INCLUDING A MALE PORTION FOR INSERTION INTO THE APERTURE OF A CO-OPERATING FEMALE PORTION OF THE OTHER RETAINING ELEMENT OF SAID PAIR, AND A LIP ON SAID MALE PORTION DIRECTED AGAINST THE DIRECTION OF INSERTION INTO THE CO- 